You can be sentenced up to an additional 10 years for using a gun.
Which is why we need the right who clamors for 'no discretion in sentencing' to lose.
The gun penalties are clearly designed to discourage people who are criminally minded from walking around with guns that make crimes more likely, but in this case there's no such issue, the officer making the mistake did nothing wrong by having a gun and it's pointless to add to his punishment for having one.
The 'non-discretionary sentencing' is just usually injustice done to placate the right-wing paranoia of authority that pervades their views from politicians to judges.
Last night, there was a show on about women in relationships with drug dealers, who got sentences like 24 years based on extensive drug dealing they might not even have known about because of mandatory sentencing, where even if they did a small thing to help their man, their sentence was mandatory to treat them as 'full participants in all the crime'.
I'm not a big fan of this 'collective justice' legislation. It's satisfying to some by giving longer sentences to everyone involved, but is it justice?
I remember a western movie where the story was that a young man wanted for murder in a robbery had the issue of, was he the guy who had shot someone or not?
A very sympathetic view of him was made if he did not shoot the man - which turned out to be the case, and he got lighter justice and the girl.
But under these laws, they'd say 'it doesn't matter if you were against shooting the man and your fellow robber did it, you are equally guilty'.